A Guide to Female Flowering and Sinsemilla Plants with Jorge Cervantes and Seedsman | Cannabis Culture


Female cannabis is prized for heavy, potent resin production and weighty flower yield. Ideal female plants grow squat and bushy with branches close together on the stem and dense foliage on branches. In most strains, the first signs of female flowers appear one to three weeks after inducing flowering with the 12-Blue Mistic hour photoperiod. High-quality feminized cannabis seeds can be purchased from reputable online seed companies like Seedsman.com.

Female flowers initially appear near the top of the terminal bud and gradually develop on lower branches starting at the tips and moving downward. Flowers have two small one-quarter to one-half-inch (6–12 mm) fuzzy white hairs called “pistils” that form a V.

The set of pistils is attached at the base to an ovule, which is contained in a light-green pod called a “calyx.” Pistil-packed calyxes form dense clusters or buds along stems. A cluster of buds is often called a “top” or “cola.” The masses of calyxes develop rapidly for the first four or five weeks, after which they grow at a slower rate.

Buds put on much of their harvest weight as they swell during the last two or three weeks of growth. Pure sativas, including Thai varieties, can flower for four months or longer! Once the ovule has been fertilized by male pollen, rapid calyx formation and resin production slow, and seed growth starts.

At this stage of flowering, taking photographs is an ideal way to track your progress and observe growth patterns. You can also use these photos to enter the Seedsman Photo Cup, which is explained in a little more detail below.

Flowering Female “Sinsemilla” Plants

Unpollinated female flower buds develop without seeds, known as “sinsemilla.” Sinsemilla flower buds continue to swell and produce more resin while waiting for male pollen to successfully complete their life cycle. After weeks of heavy flower and cannabinoid-laden resin production, THC production peaks out and buds are ready to harvest.

Sinsemilla Flowering

Sinsemilla (pronounced sin·seh·mee·yah) is derived from two Spanish words: “sin” = without and “semilla” = seed. Sinsemilla is the word that describes flowering female cannabis tops that have not been fertilized by male pollen.

Highly prized sinsemilla buds are the most potent part of any strain, with a proportionately large volume of THC per flower bud. When females’ flowering is at their peak, pistils swell and swell. Soon they change in color, most often from white to amber and, eventually, to reddish-brown.

Sinsemilla is all smoke with no seeds! Unpollinated female plants continue to flower until calyx formation and resin production peak out—six to ten weeks after turning the lights to 12 hours.

During six to ten weeks of flowering, calyxes develop and swell along the stem, yielding more high-quality buds than pollinated, seeded flowers.

Make any female marijuana sinsemilla by removing male plants as soon as they are identified. Removing males virtually guarantees that male pollen will not fertilize female pistils, but sometimes premature male flowers shed a few early grains of pollen. Sometimes an intersex (hermaphrodite) with a few male flowers will sprout on a predominately female plant. Pollen dispersed from wild or cultivated male cannabis plants could also be floating in the air.

In collaboration with the author of this grow guide, Jorge Cervantes, Seedsman are delighted to be able to invite you to participate in their inaugural Photo Cup. With a cash and prize pool worth over $40,000, this is one of the largest ever competitions of its kind and is super easy to enter. Head to the Seedsman Photo Cup page now to get involved!